--- title: Chat und Commands layout: default root: ../.. idx: 4.2 description: Registrierung eines Chatbefehls und Behandlung von Chatnachrichten mit register_on_chat_message redirect_from: /de/chapters/chat.html cmd_online: level: warning title: Offline players can run commands message:

A player name is passed instead of a player object because mods can run commands on behalf of offline players. For example, the IRC bridge allows players to run commands without joining the game.

So make sure that you don't assume that the player is online. You can check by seeing if

minetest.get_player_by_name
returns a player.

cb_cmdsprivs: level: warning title: Privileges and Chat Commands message: The shout privilege isn't needed for a player to trigger this callback. This is because chat commands are implemented in Lua, and are just chat messages that begin with a /. --- ## Einleitung Mods können mit dem Spielerchat interagieren, einschließlich Senden von Nachrichten, Abfangen von Nachrichten und Registrieren von Chat-Befehlen. - [Senden von Nachrichten an alle Spieler](#senden-von-nachrichten-an-alle-spieler) - [Sending Messages to Specific Players](#sending-messages-to-specific-players) - [Chat Commands](#chat-commands) - [Complex Subcommands](#complex-subcommands) - [Intercepting Messages](#intercepting-messages) ## Senden von Nachrichten an alle Spieler Um eine Nachricht an alle Spieler im Spiel zu senden, rufe die Funktion chat_send_all auf. ```lua minetest.chat_send_all("Dies ist eine Chat-Nachricht an alle Spieler") ``` Hier ist ein Beispiel dafür, wie dies im Spiel aussieht: Sehen Sie sich diesen Eingang an Dies ist eine Chat-Nachricht an alle Spieler Was ist damit? Die Nachricht erscheint in einer separaten Zeile, um sie vom Spieler-Chat im Spiel zu unterscheiden. ## Sending Messages to Specific Players To send a message to a specific player, call the chat_send_player function: ```lua minetest.chat_send_player("player1", "This is a chat message for player1") ``` This message displays in the same manner as messages to all players, but is only visible to the named player, in this case, player1. ## Chat Commands To register a chat command, for example `/foo`, use `register_chatcommand`: ```lua minetest.register_chatcommand("foo", { privs = { interact = true, }, func = function(name, param) return true, "You said " .. param .. "!" end, }) ``` In the above snippet, `interact` is listed as a required [privilege](privileges.html) meaning that only players with the `interact` privilege can run the command. Chat commands can return up to two values, the first being a Boolean indicating success, and the second being a message to send to the user. {% include notice.html notice=page.cmd_online %} ## Complex Subcommands It is often required to make complex chat commands, such as: * `/msg ` * `/team join ` * `/team leave ` * `/team list` This is usually done using [Lua patterns](https://www.lua.org/pil/20.2.html). Patterns are a way of extracting stuff from text using rules. ```lua local to, msg = string.match(param, "^([%a%d_-]+) (*+)$") ``` The above code implements `/msg `. Let's go through left to right: * `^` means match the start of the string. * `()` is a matching group - anything that matches stuff in here will be returned from string.match. * `[]` means accept characters in this list. * `%a` means accept any letter and `%d` means accept any digit. * `[%a%d_-]` means accept any letter or digit or `_` or `-`. * `+` means match the thing before one or more times. * `*` means match any character in this context. * `$` means match the end of the string. Put simply, the pattern matches the name (a word with only letters/numbers/-/_), then a space, then the message (one or more of any character). The name and message are returned, because they're surrounded by parentheses. That's how most mods implement complex chat commands. A better guide to Lua Patterns would probably be the [lua-users.org tutorial](http://lua-users.org/wiki/PatternsTutorial) or the [PIL documentation](https://www.lua.org/pil/20.2.html).

There is also a library written by the author of this book which can be used to make complex chat commands without patterns called Chat Command Builder.

## Intercepting Messages To intercept a message, use register_on_chat_message: ```lua minetest.register_on_chat_message(function(name, message) print(name .. " said " .. message) return false end) ``` By returning false, you allow the chat message to be sent by the default handler. You can actually remove the line `return false` and it would still work the same, because `nil` is returned implicitly and is treated like false. {% include notice.html notice=page.cb_cmdsprivs %} You should make sure you take into account that it may be a chat command, or the user may not have `shout`. ```lua minetest.register_on_chat_message(function(name, message) if message:sub(1, 1) == "/" then print(name .. " ran chat command") elseif minetest.check_player_privs(name, { shout = true }) then print(name .. " said " .. message) else print(name .. " tried to say " .. message .. " but doesn't have shout") end return false end) ```